There is a sizable research literature on surgical preparation that suggests the importance of patients' preoperative experiences and preparation for achieving smoother, quicker surgical recoveries. Absent from this literature is consideration of the impact if fellow patients (e.g., roommates) on the emotional status and recovery of surgical patients. The proposed study seeks to determine and to understand the effects of preoperative roommate assignments on the emotional well-being and hospital recovery of surgery patients. Participants (N=240) will be male surgery patients scheduled to undergo either transurethral prostatectomy or coronary-bypass surgery . One hundred and twenty patents of each surgery type will be randomly assigned before surgery to a roommate who is either similar or dissimilar in his type of surgery and either similar or dissimilar in his surgical status. The specific goals are a) to determine the preferences of preoperative patients for the different possible roommate assignments; b) to assess the nature of patient interactions prior to surgery as a function of the different roommate assignments; c) to determine the actual effects on anxiety and surgical outcome of being assigned before surgery to the different roommate conditions; d) to determine the degree to which the anticipated roommate effects generalize across the different surgery groups; e) to determine the degree to which the anticipated roommate effects on length of stay are mediated by effects on recovery behaviors; and f) to determine the degree to which the anticipated roommate effects are moderated by patients' preferences for roommate assignments. Outcome effects will be determined via medical records, patent's self-report, and behavioral indicators. The broader goals are a) to contribute to the development of a policy for preoperative roommate assignment in hospitals that is salutary for patients and yet cost-beneficial for staff to implement, and b) to simultaneously test and refine relevant basic psychological theories of stress and affiliation relationships.